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石油类污染物在包气带中迁移转化研究
Study on the Migration and Transformation of Oil-contaminants in Vadose Zone
【作者】 邓韬;
【导师】 王文科;
【作者基本信息】 长安大学 , 环境工程, 2010, 硕士
【副题名】以曹妃甸地区为例
【摘要】 随着现代工业的发展,石油作为重要的能源及工业原料被广泛的应用,而石油在开采、运输、加工等过程中会对土壤及地下水造成严重的污染。本文以曹妃甸为研究区域,选取石油类污染物作为研究对象,以资料收集整理、理论分析研究为基础,通过室内静态吸附试验及微生物自然降解试验,获取相关参数并利用数学模型模拟了石油类污染物在包气带中的分布特征,从而揭示了石油在包气带中的迁移转化规律。通过室内试验及数值模拟研究,得到以下几点研究成果:(1)研究区域中四种典型的土壤(粉砂、砂粉土、粉土、粉质粘土)在20℃时吸附平衡时间都在1h左右,其动力学吸附符合Lagergren拟二级动力学方程。(2)研究区域中粉砂、粉土及砂粉土对石油的吸附等温曲线符合Langmuir吸附模式,其理论最大吸附量分别为0.337mg/g、12.94mg/g、4.606mg/g。粉质粘土由于吸附能力较大,造成平衡浓度处于较小的范围中,其等温曲线符合线性吸附模式。(3)以粉砂作为典型介质,利用HDRUS—1D软件模拟了石油类污染物在包气带中的运移规律,结果表明:①在定水头入渗连续污染的情况下,污染物大约在200d左右穿透5m的包气带进入地下水,其浓度达到初始浓度;而在定水头一次污染的情况下,由于污染物被吸附和降解,其浓度随着埋深的增大而减小。②在降雨蒸发条件下,污染物经过10a的运移,滞留在地表,最大入渗深度仅在20cm左右,反映出蒸发及吸附作用对石油类污染物的下渗有一定的阻滞作用。由上述研究结果可知,高浓度的石油废水有压入渗的情况下,对地下水的威胁最大,在短时间内能到达地下水,而落地石油在自然降雨条件下对地下水的污染威胁较小。本次研究为曹妃甸地区的土壤及地下水资源的保护利用提供了科学依据。
【Abstract】 With the development of modern industry, oil as an important energy and Industrial raw materials are widely used, but Oil will cause serious soil and groundwater pollution in mining, transportation, processing.Based on caofeidian region, This article select for petroleum contaminants as the research object, Through static adsorption experiments and microbial degradation experiments in data collection, analysis and study theory basis, which get natural related parameters, there are simulate the distribution characteristics of oil in vadose zone by mathematical model, and study transportation and transformation of oil in the vadose.By laboratory experiments and numerical simulation studies, research results are the following:(1) By batch adsorption test, the adsorption equilibrium time of four typical soil samples(Silt, sand silt, silt, silty clay) in 20℃in caofeidian is about 1h, the dynamic adsorption found Lagergren pseudo second order kinetic equation.(2) Oil adsorption isotherms of silt, silt and sand silt were fit to Langmuir adsorption model, The maximum adsorption capacity was 0.337mg/g,12.94mg/g,4.606mg/g. Because Silty clay has large adsorption capacity, resulting in a smaller range of equilibrium concentration, its adsorption isotherms were fit to linear models.(3) In this dissertation, According to the regional distribution of soil, as a typical silty sand medium, and a software HYDRUS-1D is utilized to simulate and forecast transportation and transformation of oil pollutants in the vadose.①In the case of Continuous pollution of vertical infiltration, oil Penetrate Vadose zone into groundwater in about 200d, that the Concentration reach Initial concentration.Pulse of pollution in the fixed head case, because contaminants are adsorbed and degradation, its concentration and decreases with depth.②Evaporation of rainfall conditions, Oil remaining in the surface of soil depth of 20~30cm through 10a, for the soil retards petroleum pollutants.The above study results, in the case of the high concentration of oil waste water infiltration in pressure situations, the greatest threat to groundwater in a short time to reach the ground, while in natural conditions, the oil is difficult to groundwater pollution.The research in this dissertation provides scientific support towards protection and utilization of Soil and underground water resources in delta of caofeidian.
【Key words】 Caofeidian; Oil pollution; Vadose zone; Adsorption; Mathematic modle;
- 【网络出版投稿人】 长安大学 【网络出版年期】2011年 03期
- 【分类号】X50
- 【被引频次】3
- 【下载频次】364